After sucessfully trapping the Chimera in the Mesphito and discovered Lars's half eaten body before he can get a few items, Peter Langdon entered the room and he saw Alexander playing the piano, feeling a bit pale and sick in his eyes. Peter Langdon is trying to have a convertsation with him but Alexander was about to become very delusional because he was taken over by a mind controlling parasite in his back until Peter threw the knife at the parasite, killing it and saving Alexander's life from being infected and then Alexander gave Peter Langdon some advice just before he gives Peter the key to his quarters and he was never seen again during the game.

There's a possiblity that Edgar Friendly and Project K found him and take him into a labatory to get vivisected.

By the time the main character went down the spiral stairs, the main character discovered Alexander being vivisected and his face resembles of a mouse or a rat. The main character and Alexander were having a convertsation about the machine and then Alexander told him that there was a code in one of Friendly's documents in the library to open the door for the room where the machine is located. The main character told Alexander to have a go on the machine but Alexander was too scared to go on it so the main character moved on to try the machine.

Project K.(highlighted in red) kills Alexander.

After challenging himself in the machine, the main character got a rotunda and he placed it in the music box to get another key and then he went back down to the spiral stars to see Alexander again until they have a little chat and then the main character tried both keys at the same time to unlock the door but he instead saw a message and it said " THERE IS NO ESCAPE!!!! YOU BETTER START RUNNING BECAUSE HE IS COMING FOR YOU NOW.'" although he came back and he talked to Alexander again until Project K sliced him in half with a chainsaw causing the main character to escape.